a) Field of the Invention
This invention relates to improvements in the thawing of frozen blood and/or blood plasma units. Storing blood plasma in a frozen state and then thawing it when needed is a common practice in blood banks of hospitals and the like.
b) Description of Related Art
For many years the typical practice in the blood bank has been to select the required unit of blood and/or plasma and simply place it into a controlled temperature water bath to thaw the unit to the liquid state. Sometimes this thawing procedure includes some form of secondary agitation of the bag or blood unit. After thawing, the unit is removed from the water bath and is temperature controlled for use anytime during the next twenty-four hours.
Blood and/or plasma units typically are in the form of a sealed, prepackaged plastic pouch, holding 250 milliliters or so of plasma or blood product. The pouch includes one or more connector tubes through which the product may flow when the unit is in use. The connector tubes typically are presealed with a plastic membrane which is punctured when the unit is connected to the delivery catheter, as by a needle set inserted into the tube to puncture the membrane.
U.S. Pat. No. 4,486,389 discloses a technique and system which achieves thawing in a water bath, while maintaining the plasma bag in a dry, contaminant-free configuration, wherein the frozen plasma unit is placed within a thin, open-topped plastic bag. The bag then is placed in a special holder associated with the water bath. The holder and the bag cooperate to maintain the plasma unit, which is within the lower end of the thin plastic bag, well submerged below the surface of the water. The thin, open topped plastic bag conforms closely to the shape and configuration of the frozen plasma container thereby avoiding any substantial insulative spaces which might retard the thawing process. The holder and water bath are specially constructed to facilitate easy attachment and detachment of the bag from the holder. After the thawing process has been completed, the plastic bag is removed in its entirety and the still dry, thawed plasma unit maybe removed with assurance that it has not been contaminated by bacteria as a result of contact with the thawing bath.
While prior techniques and apparatus variously disclosed provides improvement over conventional systems for thawing frozen plasma, the need still exists for a more rapid and effective thawing technique. In many instances where thawing of plasma is required, time is of the essence, and may, in fact, save lives. Therefore, the need exists for a frozen plasma thawing system having improved efficiency and reduced thawing time.